1. Field
The following description relates to cache memory systems and operating methods for the same, and more particularly, to cache memory systems for reducing cache miss possibility and operating methods for the same.
2. Description of the Related Art
Generally, a processing unit, such as a CPU, reads out and processes commands or data stored in a large-capacity external memory. Most large-capacity external memory devices feature processing speeds significantly slower than that of a CPU, and thus a cache memory system is used for enhancing processing speed.
A cache memory system stores data recently accessed by a CPU, so that, when the CPU requests the same data, the CPU may access the high-speed cache memory instead of accessing an external memory. As a result, data transmission speed may be increased.
If data requested by a CPU is stored in a cache memory (referred to as a cache hit), data stored in the cache memory is transmitted to the CPU. If the data requested by the CPU is not stored in the cache memory (referred to as a cache miss), data stored in an external memory is transmitted to the CPU.
Such cache memories may be categorized based on a mapping mechanism; a set-related cache memory utilizing a set-related mapping mechanism and a direct mapped cache memory utilizing a direct mapping mechanism. If the number of sets, which is a size of a set-related cache memory, is one, the corresponding set-related cache memory may be considered to be a direct mapped cache memory. The direct mapped cache memory is the simplest form of cache memories.